Secondary control system for underwater wells



1965 c. w. LAFITTE ETAL 3,199,595

SECONDARY CONTROL SYSTEM FOR UNDERWATER WELLS Filed Dec. 28, 1961 5 Sheets-Sheet l INVENTORSI C W. LAFITTE J. A. HAEBER EIR AGENT FIG. I

Aug. 10, 1965 3,199,595

SECONDARY CONTROL SYSTEM FOR UNDERWATER WELLS Filed Dec. 28. 1961 C. W. LAFlTTE ETAL 5 Sheets-Sheet 2 FIG. 3

n mwm iz k599i; J 7

Gag/m INVENTORSZ c. w. LAFITTE J. A. HAEBER BY: 5 714 Qulg THEIR AGENT 1955 c. w. LAFlTTE ETAL 3,199,595

SECONDARY CONTROL SYSTEM FOR UNDERWATER WELLS 5 Sheets-Sheet 3 Filed Dec. 28, 1961 FIG.

INVENTORSI C. W. LAFITTE J. A. HAEBER BY: 14.7w.

THEIR AGENT 1965 c. w. LAFITTE ETAL 3,199,595

SECONDARY CONTROL SYSTEM FOR UNDERWATER WELLS Filed Dec. 28. 1961 5 Sheets-Sheet 4 FIG. 8

FIG.

FIG. 6

INVENTORSI C. W. LAFITTE A. HAEBER BY: 14,796

THEIR AGENT Aug. 1965 c. w. LAFlTTE ETAL 3,199,595

SECONDARY CONTROL SYSTEM FOR UNDERWATER WELLS Filed Dec. 28, 1961 5 Sheets-Sheet 5 INVENTORSI C. W. LAFITTE J. A. HAEBER BYIdr FIG.

HEIR AGENT United States Patent 3,199,595 SECONDARY (IGNTRGL SYSTEM FOR UNDERWATER WELLS Carl Wintitte and .l'ohn A. Haeher, Houston, Tex., as-

signors to Shell Bil Company, New York, N.Y., a corporation of Delaware Filed Dec, 23, 1961, Ser. No. 162,693 ltl (Ilaims. (Cl. 166-665) This invention relates to apparatus for use on an underwater installation, as on an underwater wellhead assembly, and pertains more particularly to a secondary control system apparatus, a portion of which is fixedly mounted on an underwater wellhead assembly while a cooperating portion is lowerable into engagement with the first portion to supply a system for actuating and controlling the actuatable components on a wellhead assembly.

in an attempt to locate new oil fields, an increasing amount of well drilling has been conducted at ofi'shore locations, such for example, as oil the coast of Louisana, Texas and California. As a general rule, the strings of casing in a well together with the tubing string or strings extend to a point above the surface of the water where they are closed in the conventional manner that is used on land wells, with a conventional wellhead assembly being attached to the top of the casing. Attempts have been recently made to provide methods and apparatus for drilling and completing a well wherein both the well casinghead and subsequently the wellhead assembly and easing closure (1- ce are located underwater at a depth suflic-ient to allow snaps to pass over them. Preferably, the casinghead and well-head closure assemblies are located close to the ocean door. in order to install equipment of this type underwater at depths greater than the shallow depth at which a diver can easily operate, it has been necessary to design entirely new equipment for this purpose.

Thus, when drilling and completing an oil well or a gas well at an oifshore location, the well casinghead may have attached to it pieces of equipment such as wellhead connectors, blowout preventers, valves, etc., which are remotely actuatable through transmission lines extending from the wellhead assembly to a drilling barge or other operational platform positioned above the surface of a body of water. The various welhiead actuatable components or equipment may be hydraulically, pneumatically or electrically operated through hydraulic, pneumatic or electrical transmission lines extending between each of the various components and the operational platform at a remote location. As well drilling operations are being carried out at an offshore location with the wellhead assembly positioned on the ocean floor, it may happen that one or more of the transmission lines interconnecting the wellhead components to the drilling barge becomes severed or otherwise ruptured so that control of the wellhead component is lost. When such an event occurs in shallow water a diver can be sent down to replace the damaged transmission line. However, in the event that a transmission line is ruptured in deep water, such for example as a transmission line controlling the wellhead connector, it may be necessary to lower equipment to blast off the wellhead assembly and abandon the well.

it is therefore a primary object of the present invention to provide apparatus for regaining control of any one or all of the actuatable components of an underwater wellhead assembly in the event that any or all or" the control or transmission lines between the components and the control center at a distant location becomes ruptured.

A further object of the present invention is to provide apparatus comprising an auxiliary or secondary control system whereby control of wellhead components on an underwater well maybe regained upon damage to the primary control system. i

3,199,595 Patented Aug. 10, 1965 A further object of the present invention is to provide an auxiliary or secondary control system which is lowerable through great water depths then connectable to an underwater wellhead assembly for providing a control system which may be used in place of a primary control system to the wellhead components of the wellhead assembly.

Another object of the present invention is to provide a secondary control system of simple design which is engageable with a wellhead assembly for regaining control of one or more hydraulically-operated components thereof without the necessity of any hydraulic control lines running from the underwater wellhead to the drilling barge positioned at the surface of the water.

Still another object of the present invention is to proassembly, said control system being electrically actuatable.

from a remote operational platform.

A further object of the present invention is to provide apparatus adapted to be fixedly secured to an underwater wellhead assembly which is not afiectedfrom an operational standpoint by underwater conditions and is available at all times to be engaged by a secondary control system for supplying power to the wellhead components of the underwater wellhead assembly.

These and other objects or this invention will be understood from the following description taken with reference to the drawing, wherein:

FIGURE 1 is a diagrammatic view taken in longitudinal projection illustrating a floating drilling barge positioned on the surface of the ocean in which an underwater wellhead assembly is positioned on the ocean floor;

FIGURE 2 is a longitudinal view taken in cross section of one form of a male member of a secondary control system adapted to be fixedly secured to underwater wellhead assembly;

FIGURE 3 is a longitudinal view taken in partial cross section of one form of a hydraulically operated self-contained female portion of the secondary control system of the present invention;

FIGURE 4 is a longitudinal view taken in partial cross section of the male and female portions of FIGURES 2 and 3 respectively, telescopically arranged;

FIGURE 5 is a cross-sectional View of the female portion of the secondary control system of FIGURE 3 taken along the line 5 of FIGURE 4;

FIGURE 6 is a longitudinal view taken in partial cross section of another form of one portion of the secondary control system of the present invention;

FIGURE 7 is a plan view of the apparatus shown in FIGURE 6;

FIGURE 8 is a view taken in lngitudinal cross section of another form of a receiver element forming one portion of the secondary control system that is adapted to receive and have seated therein the apparatus of FIG- URE 6;

FIGURE 9 is a partial view taken in enlarged detail and partial cross section of one form of an electrically actuatable secondary control system in accordance with the present invention;

FIGURE 10 is a crosssectional view taken along the line 10-10 of FIGURE 9; and,

FIGURE 11 is an enlarged detail illustrating one form of a closure device for excluding sea water from the receiving bore of the secondary recovery unit of the present invention; and,

FIGURE 12 is a longitudinal view of a production wellhead positioned on the ocean floor.

Referring to FIGURE 1 of the drawing, a drilling platform or barge 11, of any suitable fi'oatable type is illustrated as floating on the surface of the water 12 and fixedly positioned over a preselected drilling location by being anchored to the ocean floor 13 by suitable anchors (not shown) connected to anchor lines 14. and 15. Equipment of this type may be used when carrying on well drilling operations in water depths varying from about 100 to 1400 feet or more. The drilling barge is equipped with a suitable derrick 16 as well as other auxiliary equipment needed during the drilling of a well. The derrick 16 is positioned over a drilling slot or well 18 which extends vertically through the barge in a conventional manner. When using the equipment of the present invention the slot of the barge 11 may be either centrally located or extend in from one edge. However, drilling operations may be carried out over the side of the barge without the use of a slot. Additionally, it is to be understood that the equipment of the present invention may be also used while drilling a well from any suitable operational base positioned above the surface of the water, such for example, as from a drilling barge having feet extending to the ocean floor, or from a platform permanently positioned on the ocean floor.

A typical underwater wellhead structure is illustrated in FIGURE 1 as comprising a base member 21 which is positioned on the ocean floor 13 and is fixedly secured to a conductor pipe or a large-diameter well casing 22 which extends down into a well, which has been previously drilled, and is preferably cemented therein. Thus, the base structure 21 is rigidly secured to the ocean floor in order to support two or more vertically-extending guide columns 23 andZd adapted to receive and guide therein guide arms 25 and 26, 25a and 2601, which are arranged to slide on vertically-extending guide cables 27 and 28. The lower ends of the guide cables 27 and 28 are anchored to the base structure 21 within the guide columns 23 and 24 while extending upwardly through the water to the drilling barge. 11 where they are preferably secured to constant-tension hoists 31 and 32.

Centrally positioned above the base plate 21 and fixedly secured thereto, or to the conductor pipe 22, is a well casinghead 33. The wellhead is also shown as being provided with a cement circulation or fluid return line 36 which is provided with a quick-disconnect coupling 37 and a flow control valve 38.

The guide arms 25 and 26 are illustrated as being connected to a wellhead connector 40 which is hydraulically or electrically actuated to connect on to the top of the casinghead 33. During the drilling of a well, one or more blowout preventers may be connected coaxially above the wellhead connector 40. In FIGURE 1, a series of five blowout preventers 41, 42, 43, 44 and 45 are illlustrated as being fixedly secured together and forming a unitary package with the wellhead connector which is adapted to be lowered on to the casinghead 33 in any suitable manner. Preferably the combined blowout preventers 41 through 45 and wellhead connector 40 are run into posi tion on the topof the well by being lowered through the water from the barge 11 by means of a pipe string 46 commonly known as a running string, the blowout preventer 45 being connected to the lower end of the running string 45 by means of a suitable coupling or connector 4'7 which. may be similar in form to the wellhead connector 40. During drilling operations the running string 46 is generally replaced by a large-diameter pipe string known as a marine conductor.

The various wellhead components such for example as wellhead connector 46 and blowout preventers 4145, may be either hydraulically, pneumatically or electrically actuatable but are preferably hydraulically actuatable. In the event that hydraulically actuatable components 40- 45 are employed, it is necessary that at least one and preferably two hydraulic hoses extend between the wellhead component and the drilling barge 11 at the surface. Two hydraulic hoses are generally employed to each component so as to supply a pressure fluid to engage or disengage a component, that is, to actuate it in both directions. For purposes of describing the present invention it will be assumed that the hydraulic hoses connecting the wellhead components to the barge 11 have been ruptured and torn away from the underwater installation when wind and waves moved the barge 11 from its anchored position. These pressure hoses interconnecting the wellhead components with the barge 11 form the primary control system of the wellhead components.

In addition to the primary control system for the wellhead components 3S45, the wellhead assembly in FIG- URE 1 is illustrated as being provided with one portion of a secondary control system which in the form illustrated comprises a vertically-extending cylindrical member 49 which is operationally connected to wellhead components 4t 41, 42, 43, 44 and 45 by suitable transmission lines, in this case, hydraulic lines or pressure hoses 5t 51, 52, 53, 54 and 55, respectively. Although the hoses 5tl-55 are illustrated as single hoses, they preferably contain a pair of hydraulic hoses so that each of the elements can be operated in two directions. The cylindrical member 49 may be fixedly secured at any point to the stack of blowout preventers li-45, as by means of a bracket arm 56. The member 49 is also preferably positioned within the periphery of the configuration formed by the guide columns 23 and 24 although this is not necessary.

In FIGURE 2 the cylindrical well member 49 is shown as comprising a central body mandrel 53 having a sleeve 59 slidably mounted for axial movement on the outer surface thereof. The sleeve 59 is normally maintained in its upper position, as illustrated, by means of a compression spring 60. The spring at bears against an outwardly extending flange 61 on the outside of the sleeve 59, at one end, while the other end of the sleeve bears against an internal flange 62 fixedly secured within a cylindrical spring housing 63.

The central body mandrel 58 of the well member 49 is provided with a plurality of fluid passageways 65 and 66, only two of which are shown complete for ease of illustration with portions of two other fluid passageways 67 and 68 being illustrated. As shown in FIGURE 5 the particular central body mandrel 58, illustrated, is provided with 14 separate longitudinal passageways. In FIGURE 2 it may be seen that the upper portion of the outer wall 70 forms a sealing surface which is provided with suitable seals, such as O-ring seals 7?. partially recessed in grooves '72 in the outer wall 79 of the mandrel 58. One end of each of the fluid passageways 65-68 terminates at the bottom of the mandrel 58 while the upper ends of the passageways each communicate with the sealing surface 70 of the mandrel 58 between a pair of seals '71. Thus, there is no chance of communication between the passageways when another sealing surface engages the sealing surface '70 and the seals 71. If desired, the .slidable sleeve 59 may be provided with a key 73 arranged to move vertically within the keyway '74 to prevent rotation of the sleeve 59 on the mandrel 58.

The cylindrical well member 49 of FIGURE 2 forms the male portion of the secondary control system of the present invention which is arranged to fit telescopically within a female portion of the system which comprises a cylindrical housing member 76 (FIGURE 3) having a central bore 77 extending upwardly from the bottom thereof. The housing member 76 has an inner wall 78 and an outer wall '79 with a conduit 80 extending through both walls near the upper end of the bore 77 so that any fluid in the bore 77 can be displaced out of the housing member 76 when the housing member 76 is lowered onto the cylindrical well member 49.

Mounted on the lower end of the housing member 76 is a connector unit 82 for securing the housing member 76 to the central body mandrel 58 of the cylindrical well member 49. The specific connector unit illustrated is provided with inwardly extendible locking dogs 83 adapted to be forced into the bore 77 of the housing member 76 when pressure fluid is applied through conduit above piston 85 to drive the piston downwardly so that its camming face 86 forces the dog inwardly. The dog 33 seats in annular locking grooves 87 formed on the sealing surface 70 of the central mandrel 53 below all of the radially-extending fluid passageways 65 and 66 (FIGURE 2). When the connector unit 82 is in its locked position it may be unlocked by applying pressure fluid through conduit 8% to drive the piston 85 upwardly and allow the locking dogs 83 to be retracted in the housing member 75 when the housing member is withdrawn from the well member 49. Preferably, however, the connector unit 32 is of the fail-safe type wherein, upon loss of hydraulic pressure fluid, a compression spring 89 hearing against the bottom of the piston 35 would force the piston 35 upwardly to its unlocked position.

Between the walls 73 and 79 of the housing member 76 are a series of pairs of conduits for example conduits 91 and 92 (FlGURE 3 which are either each provided with suitable valve means or are both connected to a four-way valve 93 which is supplied with a pressure fluid through conduit 94 which is in communication with the discharge 95 ot a pump 96. The other port 97 (FIG- URE 5) of the valve 93 isIin communication with the space 93 between the inner and outer walls 78 and 79, respectively of the housing member 76, which s ace 93 serves as a fluid reservoir chamber. Instead of employing a four-way valve, two three-way valves or four single valves could be used in each location.

It is to be understood that elements id'llild of FIG- URE 5 and elements 5&5 and res of FIGURE 3 are identical electrically-operated Republic Manufacturing Co., Cleveland, Ohio, Lo-Torq four-way valves in hydraulic lines, each of the lines being in communication between one port of a valve and the discharge 95 of pump as, while another port of each valve is in communication with the reservoir chamber, and the other two ports are selectively brought into communication with the fluid passageways or conduits which extend through the inner wall 78 of the housing member 76 to allow fluid flow in one direction. On selective movement of the valve to a second position, the latter two ports are brought into register with conduits in the housing member 76 to allow reversal of flow through the conduits. The pump 96 is driven by an electric motor 1% positioned within the housing member 76 and connected to the pump by means of a shaft N99. The motor 1% is supplied by power through electrical cable 110 which is a multi-strand transmission cable connecting each of the electrically-actuated four-Way valves 93, etc., to suitable switching circuits on the barge 11 at the surface of the water. The cable 110 may also be of the weight supporting type having a sheath on the outer surface or a weight-supporting core in the center. The discharge conduit 95 from the pump 96 may be provided with a pressure sensing device and circuit to start the pump when the pressure drops below a predeternnned value.

In FIGURE 4, the housing member 76 is shown in operative position on the mandrel 53 of the cylindrical well member 49. As the housing member 7 6 was lowered onto the cylindrical well member, the lower edge of the connector unit 82 on the housing member 76 contacted the upper face of the flange 61 at the top of the slidable sleeve 59, pushing the sleeve downwardly and compressing the spring 69 as the mandrel 5% moved up through the bore 77 of the housing member 76, fluid in the bore was expelled through conduit $0. In the seated position of the housing member 76, as illustrated in FIGURE 4, each of the conduits in the mandrel 53, for example conduit 65 and d6, are brought into register and communication with cooperating conduits 91 and 92 in the housing member 76. In the event that the bottoms of conduits 65 and 66 were connected to a pair of flexible conduits 111 and 112 which were bound together to form hydraulic pressure hose 5% (FIGURE 2), the wellhead connector 4%) (FIG- URE 1) could be either latched or unlatched from the casinghead by the application of pressure fluid through one hose or the other. This would be accomplished by selective switching from the barge so as to actuate electrically operated valve 93 and set it in the desired position to allow the hydraulic pump 96 to force fluid to the wellhead connector 49 in order to operate it. As shown in FY- URE 4, when the male and female portions of the secondary control system of the present invention are connected together, the locking dogs 83 are forced into the locking grooves on the outer surface of the central mandrel 58 by the piston which is shown in its lowermost position. For ease of illustration, the conduits 84 and 88 (FIGURE 3), which provide pressure fluid for actuating the piston 85 of the connector unit 32, have not been shown on FIGURE 4. Another form of a housing member 116 is shown in FIGURE 6 which is' identical inside to the housing member 76 of FIGURES 3 or 4 except that instead of being provided with a central bore 77 (FIGURE 3) extending upwardly from the bottom of the housing, the housing member 116 of FIGURE 6 has a downwardly-extending probe or mandrel element 118 which is identical to the central body mandrel 58 of FIGURE 2, being provided with a plurality of fluid passageways 119 and 120 which extend longitudinally through the mandrel element 118 and then turn at a 90 angle to discharge at the outer surface 121 of the mandrel 118 between pairs of O-ring seals 122. Other discharge ports are shown at 123 and 124. In the arrangement of the housing member 116 shown in FIGURE 6, the connector unit 125 at the lower end thereof may be of similar construction and be piston-operated in a manner similar to the connector unit 82 of FIGURE 3 eX- cept that the locking dogs 126 would move outwardly to engage locking grooves 127 on the inner wall or seaing surface 12% of a tubular well member 129 which would be mounted on the bracket 56 (FIGURE 1) in place of the cylindrical well member 49, and serve the same purpose. That is, the tubular well member 129 would be provided with a plurality of fluid passageways 131 and 131 through the wall thereof which will be in communication with pressure hoses 132 and 133 and be adapted to be connected in pairs and run to one of the wellhead components to which pressure fluid was supplied to actuate the component from one position to another. In the arrangement shown in FIGURE 8, the inner wall or sealing surface 128 of the tubularv well memher 129 would be normally protected by a slidable sleeve 134 having a flange 135 thereon against which compression spring 136 can act while the lower end of the spring would bear against flange 137 at the bottom of the tubular well member 129.

When the probe or mandrel element 113 of the housing member 115 (FIGURE 6) was forced into the tubular well member 12% (FIGURE 8) the lower end of the mandrel element 218 would force the sleeve 134 downwardly with the lower end of the sleeve protruding out the bottom of the tubular well member, while the discharge ports 123, 124, 119 and 12b of the mandrel element 113 would be brought in communication with their corresponding ports such as 13% and 151 of the tubular well member 129 (FIGURE 8).

In order to lower the housing members 76 or 116 into place on the cooperating well members 39 and 129, respectively, as shown in FIGURE 6 the housing member 116 is provided with two or more guide arms res and 1 21 which have guide cones 142. and 143 at the ends thereof that are adapted to slide down the guide cables 27 and 28 (FIGURE 1) and slide down within the guide columns 23 and 2.4 so that the housing member would be accurately aligned overits mating well member 49' (FIG- URE 1). It is to be understood that the guide arms 140 and 141 would necessarily be of diiierent lengths in the arrangement illustrated since the cylindrical well element 49 is closer to the guide column 24 than it is to the column 23. Any other suitable type of guide device or framework may be employed for lowering the housing member and guiding it into aligned telescoping engagement with the well member 48. Alternatively, the housing member 76 or 116 could be lowered into place by any suitable underwater manipulator. During the lowering of the housing member 76 into place on the wellhead assembly at the ocean floor, the bore 77 may be filled with a heavy grease if desired, to keep the sea water out. As the housing member 76 was stabbed down over the central body mandrel 58, the grease would be forced out of the top of the bore 77 through conduit 89. Alternatively, the lower end of the bore 77 may be provided with a plug 145 having O-ring seals 145 and 147 so as to hold the oil or grease within the bore '77. The plug 145 would be held in place by suitable latches 1 53 and 149 provided with compression springs 15! and 151 which allow the latches 148 and 14-9 to retract when forced inwardly by the point of the centralbody mandrel 58.

It may be seen that by employing the secondary control system of the present invention, it is possible to reestablish control of wellhead components at the ocean floor after the primary control system of these elements has been lost through accident or for some other cause. Thus, after losing control of the wellhead components, the housing member of the present invention is put on its frame and lowered from the barge 11 (FIGURE 1) into aligned engagement with the mating well member 4-9 positioned on the wellhead. Since the housing member 7 6 is a self-contained unit having its own pump, valves, motor and conduits, control of the wellhead components may be re-established through the secondary control system of the present invention by the proper selection of the switching circuits at the surface which will transmit the necessary signals through the transmission cable 110 to selectively actuate the desired number of valves within the housing member and open the necessary valves so that pressure fluid may be pumped to the desired well components to actuate them in the direction desired. It is to be understood that the control system of the present invention may also be employed as a primary control system for wellhead components thus permitting the elimination of thousands of feet of heavy high-pressure hoses which are both subject to damage and very ditlicult to handle, especially in heavy seas. When used as a primary control system the control system of the present invention may be assembled along with the wellhead components on the barge with the housing member 76 on the central body mandrel 58 when the well compo nents are originally lowered into place at the ocean floor. Alternatively, the housing member 76 could be installed later, While the conduits (9-55 are illustrated in FIG- URE 1 as being apparently flexible and subject to damage in their exposed position, it is to be understood that these conduits are normally rigid metal conduits mounted close to the equipment. While the secondary control system of the present invention has been described with regard to being used on an underwater well installation, it may also be used on other underwater installations such as oil handling or oil storage installations of vessels that are positioned on the ocean floor or at least at some distance below the surface of the body of water.

Although the secondary control system of the present invention has been described hereinabove in its preferred form, that is, a hydraulically-operated apparatus for controlling hydraulically-operated wellhead components, it is to be understood that the apparatus of the present invention could be readily adapted for use on installations employing electrically-operated components. Thus, in FIGURES 9 and the lower portion of a housing member 152 is illustrated as being provided with a downwardly-extending mandrel member 153 which may be provided with connector means (not shown) similar to the connector 125 on mandrel 118 of the housing member 116 (FIGURE 6). Instead of being provided with hydraulic transmission means in the form of conduits for handling a pressure fluid, the mandrel member 153 (FIGURE 9) is provided with electrical transmission conduit means including electrical relays instead of valves and a series of electrical contact elements 154, 155 and E55. Each of the contact members, for example, contact member 154, is arranged to engage a conductor ring 357 mounted on the inner wall of an insulation portion 158 of a tubular well member 159 which is similar to tubular well member 1129 of FEGURE 8. Each of the annular conductor rings 157 is provided Witt electric conduits or leads extending through the wall of the tubular well member 159 and then run to a prime mover, such for example as an electric motor (not shown), on an electrically-actuated wellhead component. In practice these wellhead components would be the same as those illustrated with regard to FIGURE 1. In the event that a three-phase motor was used to actuate blowout preventcr 41 (FIGURE 1), three sets of electric l ads 1:51, 16%) and 162 from conductor rings 157, M3 and K4 would be employed to actuate the motor. Other pairs or sets of the contacts and conductor rings carried by the mandrel member 153 and the tubular well member 159, respectively, would be employed to operate other Wellhead components.

If it is desired to obtain pressure readings from various points in the wellhead assembly, the central body mandrel 5t and the housing member 76 would be provided with one or more registering conduits, similar to conduits 65 and 91, which would be in communication between the zone in the well assembly from which a pressure reading was to be obtained and a Norwood pressure transducer or other pressure indicating device carried in the housing member 76 and capable of transmitting a pressure signal up the cable 119 to the surface.

While the system of the present invention has been described as comprising wellhead components 4th to having a primary control system having a plurality of pressure hoses extending from the wellhead components 49 to 45 to the barge 11, and a secondary control system in accordance with the present invention, it is to be understood that the primary control system may be omitted and the so-called secondary control system would constitute the sole control system for the wellhead components. Thus, when the wellhead components were originally run down to the ocean floor during drilling operations, the housing member 76 could be attached to the body mandrel 5i and lowered into place along with the components it? to 45. Alternatively, the housing member 76 could be lowered subsequently thus permitting the lowering of the components into place without control hoses attached thereto which are subject to damage.

The control system of the present invention also has utility as the primary or secondary control system of an underwater production wellhead which normally includes such wellhead components as power-actuated master control and swab valves, wellhead closures or lockdown devices, flow line connectors, etc. In FIG- URE 12 of the drawing an underwater production wellhead is diagrammatically illustrated as comprising a casing string 17d, a production tubing string 171, a power-actuated wellhead closure 172, a power-actuated master valve 173, a power-actuated swabbing valve 174, a power-actuated fiow line connector in flow line 176, a power-actuated flow control valve 177, a well closure plug 179, and a central body mandrel 184i and a housing member 181 which are similar to the central body mandrel 58 and the housing member 76, previously described. The power-actuated components 172, 173, 174, 175 and 177 of the product-ion wellhead are operatively connected by means of control conduits to the base of the central body mandrel 18%) in a manner similar. to that described with regard to mandrel 58. The control cable 182 from the housing member 181 is shown as dropping to the ocean floor and running therealong to shore or to a control station along with the flow line 176. The control housing member 181 can be lowered with the production wellhead assembly into place or can be subsequently positioned on the mandrel see after the wellhead has been lowered to the ocean floor. A new housing member 181 can be installed at any time.

We claim as our invention:

1. A control system for an underwater well installation, said system comprising (a) a housing member lowerable through a body of water to an underwater well assembly, said housing member having first'sealing surf-ace means thereon,

(b) a plurality of conduit means in said housing member with an end of each of said conduit means terminatin g at said first sealing surface means,

(c) valve means carried by said housing member in said conduit means for controlling the flow of fluid therethrough,

(d) a source of pressure fluid in communication with conduit means of said housing member,

(e) a mating well member fixedly secured to said underwater well installation and adapted to support said housing member,

(1) said well member having second sealing surface means arranged thereon to be positioned adjacent said first sealing surface means of said housing member,

(f) a plurality of conduit means through said well member, one end of each of said conduit means terminating at said second sealing surface means and in fluid communication with conduit means in said housing member, the other end of each of said conduit means terminating at another surface of said well member,

(g) said housing member and said mating well member including positioning means carried by at least one of said members for positioning said first and second sealing surface means in substantial 'face to face engagement, and seal means carried between said first and second sealing surfaces for sealing the space therebetween in a fluidtight manner, said means isolating said cooperating conduit means.

2. The apparatus of claim 1 wherein said housing member is provided with downwardly-extending probe means and said first sealing surface means are formed on the exterior of said downwardlyextending probe means.

3. The apparatus of claim 1 wherein said housing member is provided with a vertical bore therein opening from the bottom thereof and said first sealing surface means is formed on the wall of said vertical bore.

4. The apparatus of claim 3 including guiding means at least a portion of which is carried by said housing member for aligning said housing member on said mating well member.

5. A control system for an underwater Well installation, said system comprising (a) a housing member 'lowerable through a body of water to an underwater well assembly, said housing member having first sealing surface means thereon,

(1) said housing member having a vertical bore portion therein opening from the bottom thereof,

(2) said first sealing surface means being formed on the wall of said bore portion,

(b) a plurality of conduit means in said housing member with an open end of each of said conduit means terminating at said first sealing surface means,

(c) electrically-actuatable valve means carried by said housing member in said conduit means for controlling the how of fluid therethrough,

(1) said valve means having electrical transmislb sion means extending out through said housing member to a remote location,

(d) a source of pressure fluid carried by said housing member,

(1) said pressure fluid source being in communication with the conduit means of said housing member,

(e) a mating well member fixedly secured to said underwater well installation and adapted to be positioned within the bore of and support said housing member in telescopic arrangement,

(1) said well member having second scaling surface means arranged thereon in substantial contact with said first sealing surface means of said housing member,

(f) a plurality of conduit means through said well member, one end of each of said conduit means terminating at said second sealing surface means and in fluid communication wth conduit means in said housing member, the other end of each of said conduit means terminating at another surface of said well member and adapted to communicate with a hydraulically-actuated wellhead component, and

(g) seal means carried between said first and second sealing surfaces for sealing the space therebetween in a fiuidtight manner, said sealing means isolating said cooperating conduit means.

6. The apparatus of claim 5 including weight-supposting and electrical-transmission cable means secured to said housing member for lowering said housing member into telescopic engagement on said well member.

'7. The apparatus of claim 5 wherein said well installation is a drilling wellhead assembly and includes blowout preventer means and wellhead connector means, and including conduit means in communication between the other end of said conduit means in said well member and the pressure-mid ports of said blowout prevente-r means and well head connector means forming part of a drilling wellhead assembly.

3. The apparatus of claim 5 wherein said well installation is a production wellhead assembly including hydraulically operated valve means and wherein said mating well member is fixedly secured to said production wellhead assembly with said hydraulically-operated valve means and conduit means in communication between said valve means and the other ends of said conduit means in said well member.

9. A control system for an underwater well installation having at least one hydraulically-actuated component, said system comprising (a) a housing member lowerable through a body of water to an underwater well assembly, said housing member having first sealing surface means thereon,

(1) said housing member having a vertical bore portion therein opening from the bottom thereof,

(2) said first sealing surf-ace means being formed on the wall or" said bore pontion,

(b) a plurality of conduit means in said housing member with an open end of each of said conduit means terminating at said first sealing surface means,

(c) electrically-actuated valve means carried by said housing member in said conduit means for controlling the flow of fluid therethrough,

(1) said valve means having electrical transmission means extending out through said housing member to a remote location,

(d) a source of pressure fluid carried by said housing member,

( 1) said pressure fi-uid source comprising a pressure fluid reservoir, pump means having intake means in communication with said reservoir, manifold means connecting said pump means discharge to the pressure ports of said valve 1 1 means and said reservoir means with the discharge ports of said valve means,

(e) control circuit means for said pump means and said valve means extending through said housing member to a remote location,

( f) a mating Well member fixedly secured to said underwater Well installation and adapted to be positioned within the bore of and support said housing member in telescopic arrangement,

(1) said well member having second sealing surface means arranged thereon to engage said first sealing surface means of said housing member,

(g) a plurality of conduit means through said Well member, one end of each of said conduit means terminating at said second sealing surface means and in fluid communication with conduit means in said housing member, the other end of each of said conduit means terminating at another surface of said well member and adapted to communicate with a hydraulically-actuated component on said well installation, and

(h) seal means carried between said first and second sealing surfaces for sealing the space therebetween in a fluidtight manner, said sealing means isolating each of said cooperating means.

it The apparatus of claim 9 wherein said valve means includes a four-Way valve in a pair of conduits for interconnecting said conduits one at a time with the pressure and discharge ports of said valve.

References Cited by the Examiner UNITED STATES PATENTS 20 CHARLES E. OCONNELL, Primary Examiner.

NORMAN YUDKOFF, Examiner. 

1. A CONTROL SYSTEM FOR AN UNDERWATER WELL INSTALLATION, SAID SYSTEM COMPRISING (A) A HOUSING MEMBER LOWERABLE THROUGH A BODY OF WATER TO AN UNDERWATER WELL ASSEMBLY, SAID HOUSING MEMBER HAVING FIRST SEALING SURFACE MEANS THEREON, (B) A PLURALITY OF CONDUIT MEANS IN SAID HOUSING MEMBER WITH AN END OF EACH OF SAID CONDUIT MANS TERMINATING AT SAID FIRST SEALING SURFACE MEANS, (C) VALVE MEANS CARRIED BY SAID HOUSING MEMBER IN SAID CONDUIT MEANS FOR CONTROLLING THE FLOW OF FLUID THERETHROUGH, (D) A SOURCE OF PRESSURE FLUID IN COMMUNICATION WITH CONDUIT MEANS OF SAID HOUSING MEMBER, 